U.S. demands to seize emails stored on a Microsoft server in Ireland are threatening the privacy of U.S. citizens, Microsoft said in its appeal in an ongoing lawsuit that threatens international relations and may violate European privacy laws.

Microsoft is battling a U.S. district court ruling to hand over emails to U.S. law enforcement. The company was ordered to hand over the data despite it being stored on a server in Dublin, Ireland. According to the district court, the location of the data is not relevant and seeking cooperation with Irish authorities is not necessary for a warrant’s powers to reach abroad.